Difference in Pond U.V. and Aquaria U.V.?

packaging !

just a side note. This is a 36 Watt unit, which is mucho UV for any tank under 250 gallons.

beviking said:

Thanks melonie. I realize it's a little overkill, but more uv is needed to control parasites than bacteria/algae at a given flow. IF I'm going to go this route, might as well go all the way!

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Overkill , never heard it. Jmo but uv is usually under estimated, better to go more than less if you are going to use it. And as Melonie stated the package is worth more with aquarium uv. Lol. :

Racking my own brain before getting my own UV, I did come up with the following three 'negatives' in regard to UV overkill. First, every watt of UV light is also a watt of continuous electric heat being added to your tank water. In an overkill situation on an aquarium tank, say your 36 watts of continuous water heating might become an issue i.e. needing a chiller to keep the tank from overheating. I discovered this issue as a result of already running a submerged power head/circ pump, which is already acting as an 'unwanted' source of extra electric heat.

Second, every UV unit is designed with a certain flow rate in mind. If you use that UV unit at a lower flow rate continuously, to avoid creating a maelstrom in your tank, in theory this could lead to potential problems in terms of internal temperature rise of the UV unit, degrading of the plastic assembly etc. Again I really don't know if this actually does have any bad long term side effects of any kind, or if I'm just being a paranoid sort of girl when it comes to hardware designs. Based on the fact that the turbo twist unit you're considering uses the same basic body for different lamp ratings, it's probably not an issue at all.

Lastly, UV can't distinguish between 'good' and 'bad' bacteria. Therefore running a really strong UV all the time can knock down the mobile 'good' bacteria count as well as the bad.

In my own case I went with 'only' an 8 watt UV unit on my 55 gal tank ... mostly to avoid the risk of tank overheating without a chiller. But I also picked a UV with a very large body so the relative exposure time is high (my Rainbow Lifegard body probably holds over a quart of water, versus the turbo twist body holding a few ounces). I also only run the UV two days a week ... in each case for 24 hours after my water changes to kill off any potential 'illegal immigrants' ... and then shut it off for the next 48 hours. In the event that I develop an ick/bad bacteria problem in the future, I installed my UV with a bypass valve and hose so that I can temporarily run it at say 1/4th or 1/6th of the rated flow to seriously 'zap' those nasty bugs with UV for a week. At 1/4th or 1/6th flow it will take say an hour to run all of my tank water through the UV instead of the usual 10-15 minutes, but after a couple of days those bugs will still be just as dead. But so far since installing the UV I have had zero algae or ick/bacteria problems so I have yet to actually test my theory in practice (and hopefully I never will).

PS I also run a 1 micron post-filter after my UV in my main filter 'loop', to try and pick off some of the 'dead bodies' before they get dumped back into my tank. It was surprising how much gray-black 'slime' builds up on the 1 micron filter pads after a while.

PPS I also run a totally separate HOB filter with bio-wheels to prevent the UV from directly 'pre-sterilizing' the bio-wheel water. I have no idea whether doing this is actually accomplishing anything, but I wanted extra tank flow anyhow and it can't do any harm.

PPPS I also park any 'new arrivals' in a 6 gal isolation tank for at least a couple of weeks after bringing them home, to make sure they won't act as a source of potential bacteria infection once moved to my 55 gal tank. IMHO an 'ounce of prevention' is worth an extra 28 watts of UV !
~

You do have some good points there melonie with the heat issue, but running uv 24/7 is usually not needed so the heat should not become an issue, if you did it might require the use of a chiller. As with the degrading of the plastic assembly issue, you would have to have the water running extremly slow for any significant heat build up to occur and in any case using uv would be useless because the flow would not be enough to make any impact on parasites ect .And I think they are made to withstand a lot.
The UV can't distinguish between 'good' and 'bad' bacteria as you say but in an established tank the majority of the good bacteria will be attached the the filter media or tank walls, decorations and plants ect. So the loss good bacteria to the uv will not have an impact on the tank whats so ever, in saltwater tanks housing coral however the story is completly different, it will kill a lot of plankton. I suppose the same could be said about freshwater tanks as well b/c plankton is also in freshwater.
They are good points but jmo there is really no need for concern.

Thanks for relieving my paranoia ! Actually, after thinking about the degrading plastic issue a bit longer, I came up with .... duhhhh ... the UV ray exposure itself probably posing a much more potent source of plastic degradation than any issues of temperature rise within the UV chamber (which the plastic of the UV chambers are obviously specifically designed to survive).